Genus: Rionegrochelys de la FUENTE, MANIEL, & JANNELLO, 2017
Etymology:  In reference to Rio Negro Province, Argentina, and Greek, chelys, "aquatic turtle."

Species: caldiero de la FUENTE, MANIEL, & JANNELLO, 2017
Etymology: In honor of the late Ing. Victorino Caldiero (1945-1999), for his contribution to the project of developing the southern margin of Cipolletti, Rio Negro Province, Argentina.

Holotype: MPCA-AT 258

Locality: Northern flank of the Parrita site, El Anfiteatro, Rio Negro Province, Patagonia, Argentina.

Horizon: Plottier Formation.

Biostratigraphy:

Age: Coniacian-Santonian Stage, Early Senonian Subepoch, Gulf Epoch, Early Late Cretaceous.

Material: Carapace and plasteron of an adult.

Referred material:

MPC-AT 26: Isolated plates of a carpace.

MPCA-AT 29: Right hypoplastral bone.

MPCA-AT 30: Right lateral edge of carapace with plastral bridge suture.